Place the chicken breasts into a zip-top freezer bag. Place the olive oil, chiles, garlic, shallots, cilantro, cumin seeds, lime juice and black peppercorns into a blender. Blend on high till smooth. Pour marinade over the chicken. Seal and refrigerate overnight or at least four hours.

Preheat oven to 350°F. Remove chicken from marinade, season with salt.

Heat a large sauté pan over medium-high heat and add a drizzle of grape seed oil. Sear the chicken breasts on both sides, then place into oven and cook until cooked through and the internal temperature reaches 165°F, about 10-15 minutes.